Reviewed-by: Thomas Chou thomas@wytron.com.tw
Signed-off-by: Wills Wang wills.wang@live.com ---
Changes in v7: - Define spi_cs_activate/spi_cs_deactivate - Rename MHZ to ATH79_SPI_MHZ - Use clrsetbits_32
Changes in v6: - Add rrw_delay in ath79_spi_priv for more accurate timing - Remove ath79_spi_delay - Calculate delay in ath79_spi_set_speed
Changes in v5: - remove ar933x_spi_platdata - Import document "spi-ath79.txt" from kernel - Add delay for bitbang operation
Changes in v4: - Use get_bus_freq instead of hardcode in SPI driver
Changes in v3: - Convert spi driver to driver model
Changes in v2: - Add a compatible spi driver
doc/device-tree-bindings/spi/spi-ath79.txt | 19 +++ drivers/spi/Kconfig | 8 + drivers/spi/Makefile | 1 + drivers/spi/ath79_spi.c | 237 +++++++++++++++++++++++++++++ 4 files changed, 265 insertions(+) create mode 100644 doc/device-tree-bindings/spi/spi-ath79.txt create mode 100644 drivers/spi/ath79_spi.c
diff --git a/doc/device-tree-bindings/spi/spi-ath79.txt b/doc/device-tree-bindings/spi/spi-ath79.txt new file mode 100644 index 0000000..3fd9d67 --- /dev/null +++ b/doc/device-tree-bindings/spi/spi-ath79.txt @@ -0,0 +1,19 @@ +Binding for Qualcomm Atheros AR7xxx/AR9xxx SPI controller + +Required properties: +- compatible: has to be "qca,<soc-type>-spi", "qca,ar7100-spi" as fallback. +- reg: Base address and size of the controllers memory area +- #address-cells: <1>, as required by generic SPI binding. +- #size-cells: <0>, also as required by generic SPI binding. + +Child nodes as per the generic SPI binding. + +Example: + + spi@1f000000 { + compatible = "qca,ar9132-spi", "qca,ar7100-spi"; + reg = <0x1f000000 0x10>; + + #address-cells = <1>; + #size-cells = <0>; + }; diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 2cdb110..0ab2741 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -23,6 +23,14 @@ config ALTERA_SPI IP core. Please find details on the "Embedded Peripherals IP User Guide" of Altera.
+config ATH79_SPI + bool "Atheros SPI driver" + help + Enable the Atheros ar7xxx/ar9xxx SoC SPI driver, it was used + to access SPI NOR flash and other SPI peripherals. This driver + uses driver model and requires a device tree binding to operate. + please refer to doc/device-tree-bindings/spi/spi-ath79.txt. + config CADENCE_QSPI bool "Cadence QSPI driver" help diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 3eca745..7fb2926 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -17,6 +17,7 @@ endif
obj-$(CONFIG_ALTERA_SPI) += altera_spi.o obj-$(CONFIG_ARMADA100_SPI) += armada100_spi.o +obj-$(CONFIG_ATH79_SPI) += ath79_spi.o obj-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o obj-$(CONFIG_BFIN_SPI) += bfin_spi.o diff --git a/drivers/spi/ath79_spi.c b/drivers/spi/ath79_spi.c new file mode 100644 index 0000000..568548f --- /dev/null +++ b/drivers/spi/ath79_spi.c @@ -0,0 +1,237 @@ +/* + * Copyright (C) 2015-2016 Wills Wang wills.wang@live.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <spi.h> +#include <dm.h> +#include <div64.h> +#include <errno.h> +#include <asm/io.h> +#include <asm/addrspace.h> +#include <asm/types.h> +#include <mach/ar71xx_regs.h> + +/* CLOCK_DIVIDER = 3 (SPI clock = 200 / 8 ~ 25 MHz) */ +#define ATH79_SPI_CLK_DIV(x) (((x) >> 1) - 1) +#define ATH79_SPI_RRW_DELAY_FACTOR 12000 +#define ATH79_SPI_MHZ (1000 * 1000) + +struct ath79_spi_priv { + void __iomem *regs; + u32 rrw_delay; +}; + +static inline u32 ath79_spi_read(struct udevice *bus, u32 offset) +{ + struct ath79_spi_priv *priv = dev_get_priv(bus); + return readl(priv->regs + offset); +} + +static inline void ath79_spi_write(struct udevice *bus, + u32 val, u32 offset) +{ + struct ath79_spi_priv *priv = dev_get_priv(bus); + writel(val, priv->regs + offset); +} + +static void spi_cs_activate(struct udevice *dev) +{ + struct udevice *bus = dev->parent; + + ath79_spi_write(bus, AR71XX_SPI_FS_GPIO, AR71XX_SPI_REG_FS); + ath79_spi_write(bus, AR71XX_SPI_IOC_CS_ALL, AR71XX_SPI_REG_IOC); +} + +static void spi_cs_deactivate(struct udevice *dev) +{ + struct udevice *bus = dev->parent; + + ath79_spi_write(bus, AR71XX_SPI_IOC_CS_ALL, AR71XX_SPI_REG_IOC); + ath79_spi_write(bus, 0, AR71XX_SPI_REG_FS); +} + +static int ath79_spi_claim_bus(struct udevice *dev) +{ + return 0; +} + +static int ath79_spi_release_bus(struct udevice *dev) +{ + return 0; +} + +static int ath79_spi_xfer(struct udevice *dev, unsigned int bitlen, + const void *dout, void *din, unsigned long flags) +{ + struct udevice *bus = dev->parent; + struct ath79_spi_priv *priv = dev_get_priv(bus); + struct dm_spi_slave_platdata *slave = dev_get_parent_platdata(dev); + u8 *rx = din; + const u8 *tx = dout; + u8 curbyte, curbitlen, restbits; + u32 bytes = bitlen / 8; + u32 out, in; + u64 tick; + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(dev); + + restbits = (bitlen % 8); + if (restbits) + bytes++; + + out = AR71XX_SPI_IOC_CS_ALL & ~(AR71XX_SPI_IOC_CS(slave->cs)); + while (bytes > 0) { + bytes--; + curbyte = 0; + if (tx) + curbyte = *tx++; + + if (restbits && !bytes) { + curbitlen = restbits; + curbyte <<= 8 - restbits; + } else { + curbitlen = 8; + } + + for (curbyte <<= (8 - curbitlen); curbitlen; curbitlen--) { + if (curbyte & 0x80) + out |= AR71XX_SPI_IOC_DO; + else + out &= ~(AR71XX_SPI_IOC_DO); + + ath79_spi_write(bus, out, AR71XX_SPI_REG_IOC); + + /* delay for low level */ + if (priv->rrw_delay) { + tick = get_ticks() + priv->rrw_delay; + while (get_ticks() < tick) + /*NOP*/; + } + + ath79_spi_write(bus, out | AR71XX_SPI_IOC_CLK, + AR71XX_SPI_REG_IOC); + + /* delay for high level */ + if (priv->rrw_delay) { + tick = get_ticks() + priv->rrw_delay; + while (get_ticks() < tick) + /*NOP*/; + } + + curbyte <<= 1; + } + + if (!bytes) + ath79_spi_write(bus, out, AR71XX_SPI_REG_IOC); + + in = ath79_spi_read(bus, AR71XX_SPI_REG_RDS); + if (rx) { + if (restbits && !bytes) + *rx++ = (in << (8 - restbits)); + else + *rx++ = in; + } + } + + if (flags & SPI_XFER_END) + spi_cs_deactivate(dev); + + return 0; +} + + +static int ath79_spi_set_speed(struct udevice *bus, uint speed) +{ + struct ath79_spi_priv *priv = dev_get_priv(bus); + u32 val, div = 0; + u64 time; + + if (speed) + div = get_bus_freq(0) / speed; + + if (div > 63) + div = 63; + + if (div < 5) + div = 5; + + /* calculate delay */ + time = get_tbclk(); + do_div(time, speed / 2); + val = get_bus_freq(0) / ATH79_SPI_MHZ; + val = ATH79_SPI_RRW_DELAY_FACTOR / val; + if (time > val) + priv->rrw_delay = time - val + 1; + else + priv->rrw_delay = 0; + + ath79_spi_write(bus, AR71XX_SPI_FS_GPIO, AR71XX_SPI_REG_FS); + clrsetbits_32(priv->regs + AR71XX_SPI_REG_CTRL, + AR71XX_SPI_CTRL_DIV_MASK, ATH79_SPI_CLK_DIV(div)); + ath79_spi_write(bus, 0, AR71XX_SPI_REG_FS); + return 0; +} + +static int ath79_spi_set_mode(struct udevice *bus, uint mode) +{ + return 0; +} + +static int ath79_spi_probe(struct udevice *bus) +{ + struct ath79_spi_priv *priv = dev_get_priv(bus); + fdt_addr_t addr; + + addr = dev_get_addr(bus); + if (addr == FDT_ADDR_T_NONE) + return -EINVAL; + + priv->regs = map_physmem(addr, + AR71XX_SPI_SIZE, + MAP_NOCACHE); + + /* Init SPI Hardware, disable remap, set clock */ + ath79_spi_write(bus, AR71XX_SPI_FS_GPIO, AR71XX_SPI_REG_FS); + ath79_spi_write(bus, AR71XX_SPI_CTRL_RD | ATH79_SPI_CLK_DIV(8), + AR71XX_SPI_REG_CTRL); + ath79_spi_write(bus, 0, AR71XX_SPI_REG_FS); + + return 0; +} + +static int ath79_cs_info(struct udevice *bus, uint cs, + struct spi_cs_info *info) +{ + /* Always allow activity on CS 0/1/2 */ + if (cs >= 3) + return -ENODEV; + + return 0; +} + +static const struct dm_spi_ops ath79_spi_ops = { + .claim_bus = ath79_spi_claim_bus, + .release_bus = ath79_spi_release_bus, + .xfer = ath79_spi_xfer, + .set_speed = ath79_spi_set_speed, + .set_mode = ath79_spi_set_mode, + .cs_info = ath79_cs_info, +}; + +static const struct udevice_id ath79_spi_ids[] = { + { .compatible = "qca,ar7100-spi" }, + {} +}; + +U_BOOT_DRIVER(ath79_spi) = { + .name = "ath79_spi", + .id = UCLASS_SPI, + .of_match = ath79_spi_ids, + .ops = &ath79_spi_ops, + .priv_auto_alloc_size = sizeof(struct ath79_spi_priv), + .probe = ath79_spi_probe, +};